Non-syndromic craniosynostosis: contemporary concepts in biology, diagnosis, and distraction-based operative strategy

Non-syndromic craniosynostosis is the most common clinical form of craniosynostosis, but the mature phenotype cannot be accounted for by a purely local model of premature suture fusion. The deformity is the product of interactions among calvarial growth, cranial base geometry, dural and mesenchymal signaling, orbital development, and regional soft-tissue adaptation. This narrative review examines current evidence on epidemiology, developmental biology, diagnosis, imaging, operative timing, and surgical management, with emphasis on systematic reviews, multicenter and population-based data, comparative cohorts, and larger independent series. Contemporary options-conventional cranial vault remodeling, fronto-orbital advancement and remodeling, endoscope-assisted suturectomy with postoperative orthotic therapy, spring-assisted techniques, and distraction osteogenesis-each occupy a legitimate place in selected age groups and phenotypes. This review gives particular attention to distraction because of its potential for individualized, three-dimensional correction: it is the approach in which vector, magnitude, and regional expansion can be adjusted while new bone forms and the surrounding soft-tissue envelope adapts, which is precisely what a three-dimensional deformity demands. Current comparative evidence does not establish superiority for every subtype, but the biologic rationale and available clinical results justify a broader role for distraction in contemporary reconstruction. Osteotomy design and vector geometry should follow the dominant phenotype: transverse expansion when biparietal restriction predominates in sagittal synostosis; multivector correction when orbital, skull-base, or posterior vault distortion is established; and a higher operative threshold in metopic synostosis, where true fronto-orbital narrowing-not suture fusion alone-should drive the decision. Outcomes should be judged by deformity-specific three-dimensional balance, functional safety, treatment burden, and long-term stability, and not by a single cranial index.